Electrosurgical Impedance Feedback for High-Frequency Coagulation Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electrosurgical devices face challenges in controlling energy supply to prevent thermal damage to target and surrounding tissues while ensuring proper coagulation, and accurately measuring impedance in high frequency bands.
Innovation Solution
An electrosurgical device with an impedance measuring unit and processor that controls energy supply based on impedance measurements, using a lookup table to manage energy delivery, and includes a voltage-current measuring unit with capacitors, isolation transformers, and Rogowski coils to accurately measure impedance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If high frequency electric energy is used for electrosurgical operation, then energy transfer to subcutaneous tissue is controlled and efficient energy penetration into tissue is achieved, but parasitic inductance and parasitic capacitance increase, making operation difficult
Solution Approach 1:
The patent implements a feedback control system that continuously measures impedance during electrosurgical operation and adjusts energy supply accordingly. The processor receives impedance measurement signals, compares them against reference values, and dynamically modifies energy delivery to compensate for parasitic effects, maintaining optimal energy transfer despite frequency-induced parasitic inductance and capacitance
Solution Approach 2:
The system dynamically changes operating parameters based on real-time impedance measurements. When impedance exceeds reference values indicating parasitic effects, the processor adjusts energy supply parameters (amplitude, frequency modulation) to maintain effective tissue heating while compensating for the increasing parasitic components at high frequencies
2Reliability
If excessive energy is transferred to target tissue, then coagulation is achieved, but thermal energy diffuses to surrounding tissue causing thermal damage
Solution Approach 1:
The impedance measurement system provides continuous feedback on tissue conditions. When impedance changes indicate approaching thermal damage thresholds or excessive energy transfer, the processor automatically reduces energy supply to prevent thermal diffusion to surrounding tissues while maintaining sufficient coagulation of the target area
Solution Approach 2:
The system employs periodic impedance measurements during energy delivery, creating a cycle of measurement-evaluation-adjustment. This periodic feedback allows the system to maintain energy levels sufficient for coagulation while preventing thermal damage through real-time monitoring and dynamic adjustment
3Object-affected harmful factors
If insufficient energy is transferred to target tissue, then thermal damage is avoided, but target tissue does not coagulate properly
Solution Approach 1:
The impedance feedback system continuously monitors tissue response and adjusts energy supply to ensure adequate coagulation. When impedance measurements indicate insufficient energy transfer or improper coagulation, the processor increases energy delivery to achieve proper coagulation while maintaining safety thresholds to prevent thermal damage
4Measurement precision
If impedance measurement is performed in high frequency band, then accurate tissue characterization is achieved, but measurement precision deteriorates due to parasitic effects
Solution Approach 1:
The system uses feedback from impedance measurements to compensate for parasitic effects. By continuously monitoring impedance and comparing against reference values, the processor adjusts measurement and energy delivery parameters to maintain accurate tissue characterization despite the presence of frequency-dependent parasitic inductance and capacitance
Solution Approach 2:
The system dynamically changes measurement parameters including frequency modulation and amplitude adjustment based on real-time impedance feedback. This allows the system to maintain accurate impedance measurements in the high frequency band by compensating for parasitic effects through parameter adaptation
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The device effectively controls energy supply to prevent thermal damage and ensure proper coagulation by measuring impedance in real-time, allowing operation at high frequencies without performance deterioration.
Implementation Method 1
an impedance measurement unit configured to measure an impedance of the target tissue
Implementation Method 2
energy transfer to a subcutaneous tissue layer other than a surgical site is controlled by a skin effect as the frequency is higher, and efficient energy penetration into the inside of the tissue and effective heating from the inside of the tissue are possible
Implementation Method 3
An electric surgical instrument is a medical instrument which applies electrical energy to an affected area and locally heats the affected area to simultaneously perform an incision of a target tissue and coagulation of a target tissue
Data Source
AI summary
It relates to an electrosurgical device, an impedance measuring device of the electrosurgical device, an energy control method for tissue coagulation, and an impedance measuring method, the electrosurgical device is comprised of an instrument for surgery on a target tissue, a processor configured to control energy supply to the instrument and an impedance measurement unit configured to measure an impedance of the target tissue, wherein the processor is further configured to if the impedance measured by the impedance measurement unit exceeds a first reference value, stop the energy supply to the instrument during a stop period, resume the energy supply to the instrument after the stop period has elapsed, and determine a coagulation state based on the impedance of the target tissue measured after the resumption of the energy supply by the impedance measurement unit.